10 September 2001
Early-drilling spells danger – ADAS

By Tom Allen-Stevens

LEADING crop physiologists have called on growers to pull on the brakes before drilling too early.

Yield benefits are at best dubious and growers expose themselves to increased agronomic problems by drilling early in September, they say.

“If you drill your crop early youll have top manage it very carefully to get the optimum out of it,” advises ADAS John Spink.

He points out that the yield of wheat crops only starts to drop off irretrievably if it is drilled after the end of October.

The advice follows some Syngenta-sponsored trials work, carried out at ADAS Boxworth in Cambridgeshire, which aimed for optimum yields from low inputs.

The plots, established with different drilling dates and seed rates, came out of the winter with crop cover varying from 40-350 plants/m2.

Nitrogen and growth regulator applications were managed carefully in the spring resulting in the optimum yield of 10t/ha over all the plots bar one.

The trials progress, with advice from the expert team responsible, has been followed in articles in Crops, with the results due in the 22 September issue.

Mr Spink and colleague Roger Sylvester-Bradley advises growers to manage the crop according to establishment success, rather than rely on early-drilling.

“Invariably one factor will catch you out – weeds, lodging, dry seedbeds, take-all, eyespot – theyre all classic symptoms of the early-drilled crop,” says Mr Spink.

The effect of blackgrass on early-drilled plots was trialled on part of the site that is heavily infested with a herbicide-resistant population.

Simply by delaying the drilling date, the results showed that the blackgrass population could be cut by up to 75%.

The trials underline the importance of getting a good stale seedbed before considering getting the drill out, says Syngentas Jason Tatnell.

“Where you have bad blackgrass land, that has to be your priority – youll lose far more by not going for the blackgrass than youll gain by striving for top yields.”

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